Marshall said: “Like a self-fulfilling prophecy, the new system is causing us [to say] migrant workers will not be a source – let’s look elsewhere. Where we might have looked overseas, we’re almost not looking at that any more. In the long run, the amount of immigrants we employ will go down.”

He said: “Employers will have to intensify their recruitment processes and raise their wages to attract British workers, or keep the migrant workers they do not want to lose [to make them eligible for the shortage list].”